From patchwork Tue Jan 23 23:10:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Li X-Patchwork-Id: 13528256 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A698C47258 for ; Tue, 23 Jan 2024 23:11:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=K4VuZJqGGkLJxiZkuAU1rnYFmZ9Ex0tkKle+teKuXDg=; b=j6q/2aIc35+/3Q ssq0FbyvHySG/OZEGkYUVx/lwdrOGgHETGNlmoSygF6SYYRC4oxv2FeGI3YIfeAdKS7Dms3rjqKM3 6UtOenYewnO1d76p5lXJic+5IYDKiGa8lVbCSf2grzSI/V4lqAgTpIOy2AOF5a4Hx0WuSp4qi0Y1g m7Qw1PTX5cTWpnwiMPre6s18dvXkhXU6S+V++uOoQlgPgzTjbXSuQqe4a98/SwiGPlB4gwnJXN2DY xnbDnhLbSSFiGAnX04VFcYwzIy88JRh1iyZ1VEDb3Ui7RcDb8ygPsHnJ0g8fjbdxWXm7ISAyGePwy ovMvxjqt5s43mXVdNtbg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rSPvN-000mu3-0f; Tue, 23 Jan 2024 23:11:21 +0000 Received: from mail-vi1eur05on20601.outbound.protection.outlook.com ([2a01:111:f403:2613::601] helo=EUR05-VI1-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rSPvJ-000moe-1k for linux-i3c@lists.infradead.org; Tue, 23 Jan 2024 23:11:19 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=b5yGvUhL5HplsR/B24m9rABCvZz6VKFornOA6BdLk+e1wlADKUelRZWhshT8Adqx6ZwJLDkyoSBwGwKbKIZgDTGVpLWnjjQR5oIUUfv+8xtWMV9oBiEoOO+1fZBqWESle2B+sRku0LMM6UGl5ZCnVuoc8bH5ltAH/Sg59p8UNEW/SZqCSdcSrMOrutlfXqNQrsf4Gl01nh3JqqTmNftih4SRPoqd+00H45wDcERe1gJiCtrqh/+S3aFCZdnMxXJuaXnuIG+HjKuOBonWP2uUbYbMN0ikuh1STsnl/BiLYKV3rYhrRhXtIWhyDdfgG51LETr1CH3Ll8sr8xTyay4ADQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=NcAD7n5DFC8zY5SMsqG6DN1S/Q3hAt3IaNHuvXjxowM=; b=KyZPD+kfDper0xWvB6c5pipHpcQwWUlZPfwzMjhwYUc5GiW5hw65/ys9I670iDvbbQcmOIItmIYilySQNLT6QBpijuZw+fgN66hEJgg+uVzm/tEyT6Z55yjzBt+4Ib0RmpJh1vX6SU+coRegYiTULI0p8rX6iB0ka8rTRN8zIoz4U9T4mBLdG/IDyo7LuLKVRcjHI4OvaH/YvFguYYlNFMb9PgoPJBC0zcmX/OYibM549gluLaPSvfQFBnVAnJCPqAesIIOz9kVENC5TeIA2vuWFfziY7CvKk9Dc0FLqwakxo4Pd4qFnycR/jDVZXgEHpAT3uOxpx9u/ahdB6j9Hcw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=NcAD7n5DFC8zY5SMsqG6DN1S/Q3hAt3IaNHuvXjxowM=; b=MEdYykU8PLJCHCi+n4v1YlfD/Y0rYXwnWRSY/GpldwN6YF8rvFMUSXLJldrxL9EiUD+4lp2gAKxKjeHfJn99I54U5QlrZAQQSHaghQtv6nM/PWsjtLZyCg9y4tskN4zrsmok0TYZGoP996ETcE/49oUGxaN+SBXjlJCBEwpe0ek= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from PAXPR04MB9642.eurprd04.prod.outlook.com (2603:10a6:102:240::14) by DB9PR04MB9475.eurprd04.prod.outlook.com (2603:10a6:10:367::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7202.32; Tue, 23 Jan 2024 23:11:12 +0000 Received: from PAXPR04MB9642.eurprd04.prod.outlook.com ([fe80::c8b4:5648:8948:e85c]) by PAXPR04MB9642.eurprd04.prod.outlook.com ([fe80::c8b4:5648:8948:e85c%3]) with mapi id 15.20.7202.035; Tue, 23 Jan 2024 23:11:12 +0000 From: Frank Li To: frank.li@nxp.com Cc: alexandre.belloni@bootlin.com, conor.culhane@silvaco.com, devicetree@vger.kernel.org, gregkh@linuxfoundation.org, imx@lists.linux.dev, jirislaby@kernel.org, joe@perches.com, krzysztof.kozlowski+dt@linaro.org, krzysztof.kozlowski@linaro.org, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, miquel.raynal@bootlin.com, robh@kernel.org, zbigniew.lukwinski@linux.intel.com Subject: [PATCH v4 3/8] Documentation: i3c: Add I3C target mode controller and function Date: Tue, 23 Jan 2024 18:10:38 -0500 Message-Id: <20240123231043.3891847-4-Frank.Li@nxp.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240123231043.3891847-1-Frank.Li@nxp.com> References: <20240123231043.3891847-1-Frank.Li@nxp.com> X-ClientProxiedBy: SJ0PR03CA0371.namprd03.prod.outlook.com (2603:10b6:a03:3a1::16) To PAXPR04MB9642.eurprd04.prod.outlook.com (2603:10a6:102:240::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PAXPR04MB9642:EE_|DB9PR04MB9475:EE_ X-MS-Office365-Filtering-Correlation-Id: 6ac074e4-0621-42bd-b55e-08dc1c68975e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PAXPR04MB9642.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(136003)(376002)(396003)(346002)(366004)(39860400002)(230922051799003)(1800799012)(451199024)(64100799003)(186009)(1076003)(83380400001)(66946007)(2616005)(26005)(6506007)(6512007)(38100700002)(478600001)(2906002)(8676002)(30864003)(34206002)(8936002)(4326008)(7416002)(37006003)(52116002)(5660300002)(66476007)(6486002)(66556008)(316002)(6666004)(36756003)(38350700005)(86362001)(41300700001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6ac074e4-0621-42bd-b55e-08dc1c68975e X-MS-Exchange-CrossTenant-AuthSource: PAXPR04MB9642.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Jan 2024 23:11:12.3976 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 9HU5XHq7dmptpV0dM4a6br3OeBxQ0SjWqKKHTgKWeEx4E8ChS3QFQ0E9M5z8q3hsPLPUhLWFT7Ak5rlQg4QJZg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB9PR04MB9475 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240123_151117_587761_EF0FF883 X-CRM114-Status: GOOD ( 22.94 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org Add I3C target mode and tty over i3c func driver document. Signed-off-by: Frank Li --- Documentation/driver-api/i3c/index.rst | 1 + .../driver-api/i3c/target/i3c-target-cfs.rst | 109 ++++++++++ .../driver-api/i3c/target/i3c-target.rst | 189 ++++++++++++++++++ .../driver-api/i3c/target/i3c-tty-howto.rst | 109 ++++++++++ Documentation/driver-api/i3c/target/index.rst | 13 ++ 5 files changed, 421 insertions(+) create mode 100644 Documentation/driver-api/i3c/target/i3c-target-cfs.rst create mode 100644 Documentation/driver-api/i3c/target/i3c-target.rst create mode 100644 Documentation/driver-api/i3c/target/i3c-tty-howto.rst create mode 100644 Documentation/driver-api/i3c/target/index.rst diff --git a/Documentation/driver-api/i3c/index.rst b/Documentation/driver-api/i3c/index.rst index 783d6dad054b6..345a43c9f61b0 100644 --- a/Documentation/driver-api/i3c/index.rst +++ b/Documentation/driver-api/i3c/index.rst @@ -9,3 +9,4 @@ I3C subsystem protocol device-driver-api master-driver-api + target/index diff --git a/Documentation/driver-api/i3c/target/i3c-target-cfs.rst b/Documentation/driver-api/i3c/target/i3c-target-cfs.rst new file mode 100644 index 0000000000000..1fcf829dc4ae2 --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-target-cfs.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================= +Configuring I3C Target Using CONFIGFS +======================================= + +:Author: Frank Li + +The I3C Target Core exposes configfs entry (i3c_target) to configure the I3C +target function and to bind the target function with the target controller. +(For introducing other mechanisms to configure the I3C Target Function refer to +[1]). + +Mounting configfs +================= + +The I3C Target Core layer creates i3c_target directory in the mounted configfs +directory. configfs can be mounted using the following command:: + + mount -t configfs none /sys/kernel/config + +Directory Structure +=================== + +The i3c_target configfs has two directories at its root: controllers and +functions. Every Controller device present in the system will have an entry in +the *controllers* directory and every Function driver present in the system will +have an entry in the *functions* directory. +:: + + /sys/kernel/config/i3c_target/ + .. controllers/ + .. functions/ + +Creating Function Device +=================== + +Every registered Function driver will be listed in controllers directory. The +entries corresponding to Function driver will be created by the Function core. +:: + + /sys/kernel/config/i3c_target/functions/ + .. / + ... / + ... / + ... / + .. / + ... / + ... / + +In order to create a of the type probed by , +the user has to create a directory inside . + +Every directory consists of the following entries that can be +used to configure the standard configuration header of the target function. +(These entries are created by the framework when any new is +created) +:: + + .. / + ... / + ... vendor_id + ... part_id + ... bcr + ... dcr + ... ext_id + ... instance_id + ... max_read_len + ... max_write_len + ... vendor_info + +Controller Device +========== + +Every registered Controller device will be listed in controllers directory. The +entries corresponding to Controller device will be created by the Controller +core. +:: + + /sys/kernel/config/i3c_target/controllers/ + .. / + ... / + .. / + ... / + +The directory will have a list of symbolic links to +. These symbolic links should be created by the user to +represent the functions present in the target device. Only +that represents a physical function can be linked to a Controller device. + +:: + + | controllers/ + | / + | + | functions/ + | / + | / + | vendor_id + | part_id + | bcr + | dcr + | ext_id + | instance_id + | max_read_len + | max_write_len + | vendor_info + +[1] Documentation/I3C/target/pci-target.rst diff --git a/Documentation/driver-api/i3c/target/i3c-target.rst b/Documentation/driver-api/i3c/target/i3c-target.rst new file mode 100644 index 0000000000000..09ae26b1f311a --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-target.rst @@ -0,0 +1,189 @@ +.. SPDX-License-Identifier: GPL-2.0 + +:Author: Frank Li + +This document is a guide to use the I3C Target Framework in order to create +target controller driver, target function driver, and using configfs interface +to bind the function driver to the controller driver. + +Introduction +============ + +Linux has a comprehensive I3C subsystem to support I3C controllers that +operates in master mode. The subsystem has capability to scan I3C bus,assign +i3c device address, load I3C driver (based on Manufacturer ID, part ID), +support other services like hot-join, In-Band Interrupt(IBI). + +However the I3C controller IP integrated in some SoCs is capable of operating +either in Master mode or Target mode. I3C Target Framework will add target mode +support in Linux. This will help to run Linux in an target system which can +have a wide variety of use cases from testing or validation, co-processor +accelerator, etc. + +I3C Target Core +================= + +The I3C Target Core layer comprises 3 components: the Target Controller +library, the Target Function library, and the configfs layer to bind the target +function with the target controller. + +I3C Target Controller Library +------------------------------------ + +The Controller library provides APIs to be used by the controller that can +operate in target mode. It also provides APIs to be used by function +driver/library in order to implement a particular target function. + +APIs for the I3C Target controller Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C controller driver. + +* devm_i3c_target_ctrl_create()/i3c_target_ctrl_create() + + The I3C controller driver should implement the following ops: + + * set_config: ops to set i3c configuration + * enable: ops to enable controller + * disable: ops to disable controller + * raise_ibi: ops to raise IBI to master controller + * alloc_request: ops to alloc a transfer request + * free_request: ops to free a transfer request + * queue: ops to queue a request to transfer queue + * dequeue: ops to dequeue a request from transfer queue + * cancel_all_reqs: ops to cancel all request from transfer queue + * fifo_status: ops to get fifo status + * fifo_flush: ops to flush hardware fifo + * get_features: ops to get controller supported features + + The I3C controller driver can then create a new Controller device by + invoking devm_i3c_target_ctrl_create()/i3c_target_ctrl_create(). + +* devm_i3c_target_ctrl_destroy()/i3c_target_ctrl_destroy() + + The I3C controller driver can destroy the Controller device created by + either devm_i3c_target_ctrl_create() or i3c_target_ctrl_create() using + devm_i3c_target_ctrl_destroy() or i3c_target_ctrl_destroy(). + +I3C Target Controller APIs for the I3C Target Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C target function driver. + +* i3c_target_ctrl_set_config() + + The I3C target function driver should use i3c_target_ctrl_set_config() to + write i3c configuration to the target controller. + +* i3c_target_ctrl_enable()/i3c_target_ctrl_disable() + + The I3C target function driver should use i3c_target_ctrl_enable()/ + i3c_target_ctrl_disable() to enable/disable i3c target controller. + +* i3c_target_ctrl_alloc_request()/i3c_target_ctrl_free_request() + + The I3C target function driver should usei3c_target_ctrl_alloc_request() / + i3c_target_ctrl_free_request() to alloc/free a i3c request. + +* i3c_target_ctrl_raise_ibi() + + The I3C target function driver should use i3c_target_ctrl_raise_ibi() to + raise IBI. + +* i3c_target_ctrl_queue()/i3c_target_ctrl_dequeue() + + The I3C target function driver should use i3c_target_ctrl_queue()/ + i3c_target_ctrl_dequeue(), to queue/dequeue I3C transfer to/from transfer + queue. + +* i3c_target_ctrl_get_features() + + The I3C target function driver should use i3c_target_ctrl_get_features() to + get I3C target controller supported features. + +Other I3C Target Controller APIs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +There are other APIs provided by the Controller library. These are used for +binding the I3C Target Function device with Controlller device. i3c-cfs.c can +be used as reference for using these APIs. + +* i3c_target_ctrl_get() + + Get a reference to the I3C target controller based on the device name of + the controller. + +* i3c_target_ctrl_put() + + Release the reference to the I3C target controller obtained using + i3c_target_ctrl_get() + +* i3c_target_ctrl_add_func() + + Add a I3C target function to a I3C target controller. + +* i3c_target_ctrl_remove_func() + + Remove the I3C target function from I3C target controller. + +I3C Target Function Library +---------------------------------- + +The I3C Target Function library provides APIs to be used by the function driver +and the Controller library to provide target mode functionality. + +I3C Target Function APIs for the I3C Target Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used +by the I3C target function driver. + +* i3c_target_func_register_driver() + + The I3C Target Function driver should implement the following ops: + * bind: ops to perform when a Controller device has been bound to + Function device + * unbind: ops to perform when a binding has been lost between a + Controller device and Function device + + The I3C Function driver can then register the I3C Function driver by using + i3c_target_func_register_driver(). + +* i3c_target_func_unregister_driver() + + The I3C Function driver can unregister the I3C Function driver by using + i3c_epf_unregister_driver(). + +APIs for the I3C Target Controller Library +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the I3C Target core provides to be used by the +I3C target controller library. + +Other I3C Target APIs +~~~~~~~~~~~~~~~~~~~~ + +There are other APIs provided by the Function library. These are used to notify +the function driver when the Function device is bound to the EPC device. +i3c-cfs.c can be used as reference for using these APIs. + +* i3c_target_func_create() + + Create a new I3C Function device by passing the name of the I3C EPF device. + This name will be used to bind the Function device to a Function driver. + +* i3c_target_func_destroy() + + Destroy the created I3C Function device. + +* i3c_target_func_bind() + + i3c_target_func_bind() should be invoked when the EPF device has been bound + to a Controller device. + +* i3c_target_func_unbind() + + i3c_target_func_unbind() should be invoked when the binding between EPC + device and function device is lost. diff --git a/Documentation/driver-api/i3c/target/i3c-tty-howto.rst b/Documentation/driver-api/i3c/target/i3c-tty-howto.rst new file mode 100644 index 0000000000000..43a129b18e938 --- /dev/null +++ b/Documentation/driver-api/i3c/target/i3c-tty-howto.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=================== +I3C TTY User Guide +=================== + +:Author: Frank Li + +This document is a guide to help users use i3c-target-tty function driver and +i3ctty master driver for testing I3C. The list of steps to be followed in the +master side and target side is given below. + +Endpoint Device +=============== + +Endpoint Controller Devices +--------------------------- + +To find the list of target controller devices in the system:: + + # ls /sys/class/i3c_target/ + 44330000.i3c-target + +If CONFIG_I3C_SLAVE_CONFIGFS is enabled:: + + # ls /sys/kernel/config/i3c_target/controllers/ + 44330000.i3c-target + + +Endpoint Function Drivers +------------------------- + +To find the list of target function drivers in the system:: + + # ls /sys/bus/i3c_target_func/drivers + tty + +If CONFIG_I3C_SLAVE_CONFIGFS is enabled:: + + # ls /sys/kernel/config/i3c_target/functions + tty + + +Creating i3c-target-tty Device +---------------------------- + +I3C target function device can be created using the configfs. To create +i3c-target-tty device, the following commands can be used:: + + # mount -t configfs none /sys/kernel/config + # cd /sys/kernel/config/i3c_target/ + # mkdir functions/tty/func1 + +The "mkdir func1" above creates the i3c-target-tty function device that will +be probed by i3c tty driver. + +The I3C target framework populates the directory with the following +configurable fields:: + + # ls functions/tty/func1 + bcr dcr ext_id instance_id max_read_len max_write_len + part_id vendor_id vendor_info + +The I3C target function driver populates these entries with default values when +the device is bound to the driver. The i3c-target-tty driver populates vendorid +with 0xffff and interrupt_pin with 0x0001:: + + # cat functions/tty/func1/vendor_id + 0x0 + +Configuring i3c-target-tty Device +------------------------------- + +The user can configure the i3c-target-tty device using configfs entry. In order +to change the vendorid, the following commands can be used:: + + # echo 0x011b > functions/tty/func1/vendor_id + # echo 0x1000 > functions/tty/func1/part_id + # echo 0x6 > functions/tty/t/bcr + +Binding i3c-target-tty Device to target Controller +------------------------------------------------ + +In order for the target function device to be useful, it has to be bound to a +I3C target controller driver. Use the configfs to bind the function device to +one of the controller driver present in the system:: + + # ln -s functions/tty/func1 controllers/44330000.i3c-target/ + +I3C Master Device +================ + +Check I3C tty device is probed + + # ls /sys/bus/i3c/devices/0-23610000000 + 0-23610000000:0 bcr dcr driver dynamic_address hdrcap + modalias pid power subsystem tty uevent + +Using Target TTY function Device +----------------------------------- + +Host side: + cat /dev/ttyI3C0 +Target side + echo abc >/dev/ttyI3C0 + +You will see "abc" show at console. + +You can use other tty tool to test I3C target tty device. diff --git a/Documentation/driver-api/i3c/target/index.rst b/Documentation/driver-api/i3c/target/index.rst new file mode 100644 index 0000000000000..56eabfae83aa4 --- /dev/null +++ b/Documentation/driver-api/i3c/target/index.rst @@ -0,0 +1,13 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +I3C Target Framework +====================== + +.. toctree:: + :maxdepth: 2 + + i3c-target + i3c-target-cfs + i3c-tty-howto +